The present invention relates to an inflation pump and, more particularly, to a high-pressure inflation pump that can be used with a high-pressure gas container to release high-pressure gas in the high-pressure gas container for inflation purposes while allowing the high-pressure gas container to be used many times to save resources.
FIG. 1 shows a conventional CO2 inflation pump 40 for rapidly inflating tires of motorcycles or bicycles. The CO2 inflation pump 40 includes a body 41 to which a high-pressure CO2 container 30 is attached. The body 41 includes a first space 411, a second space 412, and a passageway 413. A nozzle 42 is mounted to an outer end of the passageway 413. The nozzle 42 can be engaged with a valve (not shown) of a tire such that carbon dioxide in the high-pressure CO2 container 30 can flow through the passageway 314 into the tire. A piercing member 45 includes an actuating portion 451 movably received in the first space 411 and a piercing portion 452 movably received in the second space 412. A washer 454 is provided at an end of actuating portion 451 connected to the piercing portion 452. A spring 453 is mounted in the second space 412 and around the piercing portion 452 to bias the piercing member 45 to a desired level in the first and second spaces 411 and 412. A lever 43 is mounted to the body 41 and can be pivoted to press against an upper end of the actuating portion 451 outside of the body 41 so as to move the piercing section 452 downward. A sleeve 44 is mounted around a lower portion of the body 41 having the second space 412. The high-pressure CO2 container 30 is received in a space defined by the sleeve 44. In this conventional structure, the sleeve 44 includes an upper opening in threading connection with the lower portion of the body 41. When the sleeve 44 is rotated and, thus, moved upward, a bottom of the sleeve 44 pushes the high-pressure CO2 container 30 upward such that an end face 311 of a threaded end 31 of the high-pressure CO2 container 30 reaches a position below a lower opening of the second space 412. When the piercing member 45 is pressed against by the lever 43, the piercing portion 452 is moved downward and pierces the end face 311, causing outflow of high-pressure CO2 in the high-pressure CO2 container 30 to the nozzle 42 through passageway 413. A block 46 and a sealing ring 47 are optionally mounted in the lower opening of the second space 412 to provide a sealing effect at the end face 311 by the sealing ring 47.
Although the conventional CO2 inflation pump 40 can rapidly inflate a tire with high-pressure CO2 in the high-pressure CO2 container 30, the manufacturing costs are high due to complicated structure of the conventional CO2 inflation pump 40. Furthermore, the piercing member 45 is relatively long and, thus, creates considerable torque during operation. Since the high-pressure CO2 container 30 is a mass-produced consumptive product that does not require high surface precision in view of cost consideration, it is not uncommon that the end face 311 is curved and has an irregular curvature due to unevenness such that the piercing member 45 may be deformed and damaged by a force component perpendicular to the piercing direction at the piercing point where the piercing section 452 pierces the end face 311.
Furthermore, in the conventional CO2 inflation pump 40, the carbon dioxide flows from the high-pressure CO2 container 30 into the space defined by the sleeve 44 after the end face 311 is pierced by the piercing member 45. The carbon dioxide keeps flowing from the high-pressure CO2 container 30 into the space defined by the sleeve 44 when the piercing member 45 is returned to its original position. Although the sealing ring 47 can provide an airtight effect in a passageway between the first and second spaces 411 and 412 to stop inflating, the sealing effect between the sleeve 44 and the body 41 can affect the pressure-maintaining effect in the high-pressure CO2 container 30, and the manufacturing costs are increased for obtaining structure with a reliable sealing effect.